Self-locking envelope



United Statesv Patent li e SELF-LOCKING ENVELOPE Herbert Zimmerman, Sr., Brooklyn, N. Y. Application December 15, 1953, Serial No. 398,254 1 Claim. (Cl. 229-85) This invention relates to envelopes and more particularly to stationery capable of being folded to form its own envelope.

The standard envelope and the type of stationery which can be folded into an envelope, employ gummed edges or tabs to seal the envelope closed. With the increased use of the mails for advertising and soliciting funds, the average person receives many such letters which are discarded without opening because of the time and trouble necessary to tear or cut open the envelope. As a consequence of these unopened letters, advertisers and solicitors lose many sales or donations which they might otherwise receive if the letters were read.

Accordingly, it is an object of this invention to provide an envelope which can be readily and quickly opened.

Another object of the present invention is to provide a combination letter and envelope which does not require gummed edges or tabs for sealing it closed,

A further object of this invention is to provide a letter medium which does not require a separate envelope.

A feature of this invention is its simplified flap construction.

Another feature of the invention is its interlocking folds which seals the envelope closed.

A further feature of this invention is an exposed tab to facilitate the opening of the envelope.

The invention consists of the construction, combination and arrangement of parts, as herein illustrated, described and claimed.

In the accompanying drawings, forming a part hereof is illustrated one form of embodiment of the invention, in which drawing similar reference characters designate corresponding parts, and in which:

Figure l is a top plan view of the complete envelope blank forming a part of this invention with the scored fold lines shown as dashed lines.

Figure 2 is a partially folded envelope formed from the blank shown in Figure 1.

Figure 3 is a top plan view of the envelope developed from the complete folding and interlocking of the blank shown in Figure 1.

Figure 4 is a section taken on line 4-4 of Figure 3 on an enlarged scale.

Referring to the drawings, and particularly to Figures 1-4, is a single foil of paper or other suitable material cut out to form a blank 11. The blank 11 is provided with several scored lines of fold designated as 12, 13, 14, 15, and 16, which divide the blank 11 into rectangular sections or panels 17 and 18, and two smaller panels 19 and 20. The sections or panels 17 and 18 and the combined panels 19 and 20 are of substantially the same size. Panels 19 and 20 are of approximately the same size. Scoring lines 12 and 13, which are drawn inwardly and parallel to both longitudinal edges 21 and 22 of the blank 11, are impressed to provide flaps 23 and 24. One corner of each of the respective flaps 23 and 24, adjacent to the upper edge 28 of the panel 17,

2,789,753 Patented Apr. 23, 1957 is diagonally cut away as indicated at 25 and 26. This diagonal cut away facilitates the interfolding of the panels 17, 19' and 20, as will be hereinafter described. To the bottom edge of the panel 20 and integral therewith, is formed a tab 27.

When it is desired to assemble the foil blank 11, to form the envelope shown in Figure 3, the flaps 23 and 24 are folded inwardly upon the panels 17, 18, 19 and 20. (See Figure 2.) The panel 17 is then folded along the fold line 14 in the direction of the tab 27. Thereafter, panel 19 is folded upwardly along the scoring line 15 and the panel 20 is folded downwardly along the fold line 16 so that the undersurfaces of the panels 19 and 20 meet. The fold or tongue formed by the folding of the panels 19 and 20, as described, is then inserted between the panel 17 and the two inwardly folded flaps 23 and 24. The panels 19 and 20 are thrust into the aperture or pocket until the edge of the panel corners 25 and 26 bears against the panel 19 at the fold line 15 (Figure 2). The interlocking of the panels 17, 19 and 20 in this manner leaves the tab 27 projecting beyond the edge of the envelope as shown in Figure 3. Corner cuts 25 and 26 of the flaps 23 and 24 respectively, facilitates the insertion of the folded edge between the flap ends. Folding the blank 11 in the manner described, self-locks the envelope thus formed. No application of an adhesive is necessary to keep the envelope intact under normal handling.

The entire surface of the blank 11, comprising the panels 17, 18, 19 and 20, and flaps 23, 24, may be utilized for the printed or written subject matter of the letter. The underside 18 of the panel 18 which forms the outside of the envelope may be used for the name and address of the addressee. The flaps 23 and 24 not only form a means for interlocking the panels 17, 19 and 20, but in addition provide the envelope with a sealed edge on both sides. With this folded arrangement, it is possible to insert added foils or sheets of written matter into the envelope. To insert the additional sheets in the envelope, the sheets are placed so that the flaps 23 and 24 overlap two sides of the sheets. When the blank 11 is folded to form the envelope, the loose sheets are locked in place. The closed edges formed by the flaps 23 and 24 prevents any loss of the inserted papers. This feature is of particular importance in the advertising field where separate sheets of illustrations are to be distributed.

To open the envelope a pull upon the tab 27 is all that is necessary; thus eliminating tearing or cutting of the envelope. The pull upon the tab 27 withdraws the tongue comprising folded panels 19 and 20 from between the panel 17 and the two flaps 23 and 24, and the envelope is unlocked as shown in Figure 2.

It is within the purview of the present invention to use a heavy bond paper, or reenforce panel 17 so as to provide a more secure interfold between panels 17, 19 and 20. In opening the envelope, panel 17 arcuately flexes from its edge 28 to fold line 18, therefore the stiffer or less flexible the panel the more secure the selflocking seal. Various degrees of envelope security-may be achieved by selecting the proper stock for the blank.

From the foregoing disclosure, it can readily be seen that an envelope has been provided which is self-locking and does not require gummed flaps. The novel folding and inter-locking arrangement of the envelope makes opening thereof quick and easy. In addition, the envelope is so formed that it is adapted to hold additional sheets of paper therein without possible loss under normal handling.

Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States, is:

3 "A 'self-loekin'genvelofie compi'ising, a first iai-gepaiiel, a second large. panel, said large.panels being contiguous along a common edge and inwardly folded toward each other along the common edge, a first small panel conond-panel bingkdonbled back upon the -fir'st smalli'yanel" tdfdrnramirgue 'reeeivame i'thin the inwai dly' 'foldfl marginal portions adjacent the free end panel and to permit the tab member to extend outwardly therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 369,274 Cox Aug. 30, 1887 1,583,867 Benedict May 11, 1926 1,954,971 Woodward Apr. 17, 1934 of the first large- 

